These clamps were used to hold the original Fixed Tethers in place on a HANS Device. They are not used with any of the newer Vision Advantage Plus sliding tethers.
The tether clamps are a critical part of helmet retention, and this version deforms once they are installed.* If you remove and reinstall your tethers, you should replace the tether clamps. Sold in pairs, enough to install tethers on one HANS device.
*The bright orange "bridges" used with sliding tethers can be reused until they show signs of wear or damage.